Gas PipingPregunta 88 de 120
Measured along the pipe, the most remote gas outlet in a building is 78 ft from the meter. Sizing tables are printed in 10 ft length increments. Which length row should be used?
a.70 ft, because 78 is closer to 70 than to 90
b.75 ft, by interpolating between rows
c.80 ft, the next length greater than the measured length
d.78 ft, only if the table is redrawn to that value
Explicación
When the measured developed length falls between table rows, you use the next longer row, so 78 ft is sized from the 80 ft column. Rounding down to 70 ft would allow more pressure drop than the table assumes and undersize the pipe, and neither interpolating nor inventing a 78 ft row is permitted by the sizing method.
Referencia Legal: IFGC §402.4Practica las 120 preguntas gratis — sin registro.
Preguntas relacionadas de este tema
- A house is served with natural gas having a heating value of about 1,000 Btu per cubic foot. The connected appliances are a 100,000 Btu/h furnace, a 40,000 Btu/h water heater and a 35,000 Btu/h clothes dryer. What total flow, in cubic feet per hour, must the piping downstream of the meter carry?
- The same 175,000 Btu/h total connected load is served by LP-gas instead of natural gas. Using about 2,500 Btu per cubic foot for propane, what flow must the piping carry?
- A natural gas system runs from the meter through section A (12 ft), then section B (18 ft), then section C (35 ft) to the farthest appliance. Using the longest developed length method, which length is used to select the size of section A?
- A residential natural gas system is supplied at about 7 in w.c. from the utility meter. Which allowable pressure drop is normally used with the standard low-pressure sizing tables for this system?
- A gas furnace sits in a basement mechanical room. Its manual shutoff valve is installed in an adjacent storage room 9 ft away, behind a closed door. Why does this installation fail inspection?
- On which of the following appliances does the IFGC NOT require a sediment trap ahead of the appliance control valve?
Última revisión: · proceso editorial
Equipo Editorial de PrepPass · Verificado con Journeyman Plumber Licensing Exam (UPC/IPC-based) · Cómo revisamos